Enhancing Reactivity of SiC-Supported Graphene by Engineering Intercalated Metal Atoms at the Interface

Controlling the reactivity of graphene with effective yet practical physical/chemical methods has been known to be the key for many applications of graphene including graphene-based solid-state catalysis. Here, by state-of-art ab initio modeling, we present a new avenue to enhance reactivity and catalytic activity of graphene that is supported on a SiC substrate. We show that intercalated metal atoms (e.g., Ru atoms) at the SiC-graphene interface form a self-assembled two-dimensional monolayer with hexagonal lattice, and by controlling the concentration of the metal atoms, the reactivity of the supported graphene could be greatly enhanced, resulting in the chemisorption of O-2 molecule on graphene. Detailed analysis revealed that the O-2 chemisorption originates from the charge transfer of nearly one electron from the activated graphene to the O-2 2 pi* orbital. We further show that the activated graphene can be an excellent catalyst toward CO oxidation reaction.